🆕 What's new

Booleans without MEDUSA	Union, Subtract and Intersect now run in the browser when MEDUSA is not running (Manifold WASM, loaded on the first boolean) — nothing to install, school computers included. With MEDUSA running they switch to native C++ on every core by themselves. The CSG panel shows which engine worked: Manifold C++ · MEDUSA or Manifold WASM.
Export the selection	📤 Export ▾ › Include: All design or Selected shapes — every format, STEP, IFC, section and JSON project included. With a single shape, the file takes its name.
Hide the panels	☰ Panels in the menubar, or the ✕ of each panel: Tools, Objects, Properties / CSG and NassScript, one by one. H hides them all and brings back exactly what was shown.
Solar System demo	A real-date Solar System to paste into ⚡ Script, at the end of the NassScript docs — nasscad.com/nasscript_doc.html

🖱 3D View Navigation

Left click	Select an object — stays instant even on very large scenes
Left click + drag	Move selected object on the XZ plane. On multi-selection: drags the entire group — relative positions preserved, single Undo step.
Shift + click	Multi-select (N objects) — for CSG, alignment
Left drag on empty zone	Box-select — draw a selection rectangle. Shift = add to selection.
Alt + left drag	Pan full 3D — drag horizontal → left/right (XZ camera-relative), drag vertical → up/down (Y)
Alt + right drag	Pan the grid + all objects — useful for large scenes
Right click + drag	Orbit camera around the scene
Middle click + drag	Pan camera
Scroll wheel	Zoom in / out — speed set by the camera buttons /5 /2 1× ×2 ×5 ×10 (see Toolbox below)
Single click on object	Select the object (drag to move it)
Double-click on object	Each double-click moves one step: ① resize handles (drag corners or top handle) → ② dimensions (X/Y/Z values) → ③ rotation rings (3 Cura-style rings) → back to nothing. Click on empty space to leave.
Double-click on .gen object	Reopens the generator dialog pre-filled with current parameters — live edit in-place (Cubic/Cylind/Tore/Pipe/Gear/Screw/Nut/Sketch/CircularText)

⌨ Keyboard Shortcuts

Ctrl + Z	Undo — up to 200 levels
Ctrl + Y	Redo
Ctrl + D	Duplicate selection
Del / Backspace	Delete selection
Arrows ↑↓←→	Move object 1 mm (XZ plane, camera-relative)
Alt + ↑ / ↓	Move object up / down (Y axis)
Ctrl + A	Select all objects
Ctrl + C / Ctrl + V	Copy / Paste (offset +10mm X/Z) — geometry + transforms preserved
L	Show / hide 3D alignment handles
S	Magnetic snap — each press steps 1 → 0.5 → 0.1 → 0.01 → 0.001 mm → OFF. The toolbox buttons jump straight to a step.
N	Toggle light / dark theme
1 · 2 · 3 · 4 · 5	Camera views: 1 reset · 2 top · 3 front · 4 right · 5 reset
Esc	Deselect all / Cancel box-select / Close dialogs
H	Hide / show the panels — choose which ones in ☰ Panels, or with the ✕ of each panel

🔷 3D Primitives — 18 watertight

Every primitive is closed and watertight — ready to slice, ready for boolean operations, no repair step needed.

Standard primitives (toolbox)
Cube	Box 20×20×20 mm — 6 flat faces
Sphere	Configurable resolution 8–256 segs (slider in Properties) · export at 2× resolution, capped 512 · smooth shading built-in
Half-sphere	Flat-capped hemisphere — same slider as sphere
Cylinder	64 segs display / 128 segs export
Cone	64 segs / 128 export
Pyramid	4-sided pyramid — square base + triangular faces
RoofArc	Half-cylinder / vaulted roof — length W, radius H, closed caps
Tube	Hollow cylinder — outer radius Ro, inner radius Ri, height H. Parameters editable in Properties.
Lathe	Surface of revolution — 64 segs / 128 export · profile defined by spline points
3D Text	Extruded text — 6 fonts (Helvetiker R/B, Optimer R/B, Gentilis R/B) · configurable depth, bevel
Wedge	Right-angle bevel — 20mm base, triangular cross-section
Roof	Triangular gable roof — 20mm base, ridge height 10mm
Hollow box	Open box — outer size and wall thickness set in its dialog
Generator primitives (.gen — parametric, double-click to edit)
Cylind.Gen	Truncated cylinder with double chamfer — Rt, Rb, H, top/bottom chamfer 1–48 segs, N facets 12–128
Cubic.Gen	Chamfered / rounded cube — W×H×D, chamfer radius, 1–48 segments
Tore.Gen	Ultra-HD torus — ring R, tube r, N ring facets 12–256, M tube facets 6–128 — seamless
ArcSphere.Gen	Spherical sector — full angle phi 1–360°, capped, correct shading at both poles
RevSolid.Gen	Revolved solid — arc angle 1–360°. Closed caps when angle < 360°.
Pipe.Gen	Hollow pipe — straight segments + tangent bends (radius R_bend, real tube-bending). No section twist along the path. Outer wall + inner wall + sealed caps.
Gear.Gen	ISO involute gears (20° pressure angle) — module 0.5–8 mm, straight / helical / herringbone. V-pulley and timing pulley. Configurable teeth, shaft bore.
Screw.Gen	Parametric screw ISO 68-1 (M2–M24) / ASME UNC·UNF — head Hex/CHC/None · Coarse/Fine/Custom/Plain · lead-in and lead-out · 32–96 radial facets. Double-click to re-edit.
Nut.Gen	Parametric nut ISO 4032/4033 · ASME B18.2.2 — M2–M24 / imperial UNC·UNF · ISO style 4032 / ISO 4033 Tall / Custom · optional 30° chamfer. Double-click to re-edit.
Sketch.Gen	2D fullscreen sketcher — lines, circles, rectangles, arcs, Bézier. Extrude a closed contour into a solid. Trim tool, magnetic snap. Double-click to re-edit.
CircularText.Gen	Curved 3D text on arc — arch (∩) or smile (∪) · arc angle 0–340° · font size, depth, spacing · 6 fonts. Double-click to re-edit.

📥 Import — STL · OBJ · 3MF · GLB · PLY · STEP · IFC

Toolbox button or menubar 📥 Import ▾. Several files can be picked at once — they are read one after the other.

STL	Binary + ASCII — automatic centering, placed on floor
OBJ	Wavefront with vertex normals — compatible Blender, FreeCAD
3MF	Bambu Studio / PrusaSlicer format — per-object colors, multi-body
GLB	Binary glTF 2.0 — multi-part assembly and colors preserved, Draco-compressed files supported
PLY	Stanford polygon format — point clouds, scanned meshes
STEP	AP203 · AP214 · AP242 — see the dedicated section below. Also accepts `.stpz · .stpx · .stpxml · .p21`
IFC	IFC2X3 · IFC4 · IFC4X3 (BIM) — read locally, no engine needed — see the IFC section below

🧩 STEP Import — assemblies, names and real colors

STEP is the exchange format of professional CAD. NASSCAD reads the real B-Rep geometry, not a mesh approximation — part names, assembly structure and colors come through as the author saved them.

What comes in
Protocols	AP203, AP214, AP242 — files from Fusion 360, SolidWorks, Inventor, CATIA, NX, Creo, FreeCAD, Onshape
Assemblies	Every part arrives as its own object, at its real position, under its real name. A 1200-part assembly gives 1200 named objects in the list.
🎨 Colors per part	The color the designer assigned to each part is applied on import.
🎨 Colors per face	A single part can carry several colors — a painted body with a bare machined face, a label on a housing, a two-tone casing. Each face keeps its own color. Requires the NASSCAD Engine companion (see Speed below): the in-browser engine does not expose per-face colors.
Which color wins	When a file gives a part one color and its faces another, the faces win — this is the STEP standard's own rule, and it is what FreeCAD, Fusion 360 and CAD Assistant do. Some exporters leave a stale color on the part itself; NASSCAD will not show it.
Color accuracy	Colors are displayed exactly as written in the file. Open the same file in FreeCAD or Fusion side by side — the shades match.
Units	The file's own unit is read and converted — millimetres, inches, metres.
Speed
⚡ NASSCAD Engine	The NASSCAD Engine companion reads STEP natively and in parallel on your machine — several times faster, and it is what delivers per-face colors and large assemblies. Detected automatically at import; nothing to configure. Recommended for any real CAD work.
In-browser fallback	Without the companion, STEP still opens with no install and no upload — but with two real limits, measured, not assumed: colors come per part only (the in-browser engine returns no per-face color at all), and large assemblies may produce no geometry. Files up to roughly 20 MB are comfortable; well beyond that, run the companion.
Instant re-import	A file you have already imported comes back immediately from the browser cache (up to 400 MB, oldest entries dropped first). Useful when iterating on a scene.
Very large files	With the companion, hundreds of MB are handled — the import is split and streamed, with live progress. A 350 MB assembly is normal work, not an edge case. In the browser alone, that class of file is out of reach.
Geometry quality
Automatic repair	Surfaces are stitched with progressively looser tolerance, small gaps are closed, and each body is checked for watertightness.
⚠ Non-manifold notice	Bodies that cannot be made watertight are reported after import (e.g. 2 non-manifold). They display normally — only boolean operations on them are restricted until repaired.
Smooth shading	Curved surfaces are smoothed while sharp edges stay sharp — no faceted look, no rounded-off corners.

📏 PMI & GD&T — manufacturing data from AP242

Modern AP242 files can carry the drawing information inside the 3D model: dimensions, datums and geometric tolerances. When a file has it, NASSCAD reads it and shows it — no 2D drawing needed.

Dimensions	Linear, angular and diameter dimensions with their values and units
Datums	Reference frames (A, B, C…) identified and listed
Geometric tolerances	Flatness, perpendicularity, position, cylindricity… — the tolerance type is decoded and named
Graphical annotations	Feature control frames and notes drawn in 3D, placed on the part where the author put them
PMI panel	Opens automatically when a file carries PMI — a readable list beside the model. Overlays follow their part when you move it.
⚠ Limits	PMI only appears if the file actually contains it — most AP203/AP214 files do not. On some files the numeric value of a geometric tolerance is not exposed and only its type is shown. Always check against the source drawing before manufacturing.

🏗 IFC — BIM read & write

IFC is the open exchange format of architecture and construction (ISO 16739). NASSCAD opens IFC models and writes IFC4 — both entirely on your machine, offline, with no engine to start.

Import — Import ▾ › .IFC
Schemas	IFC2X3, IFC4 and IFC4X3 — read by the bundled web-ifc engine, inside the browser
Elements	Every building element (wall, slab, window, beam…) arrives as its own object, under its IFC name, grouped under the file name in the object list
🎨 Colors	The colour and transparency of each element are applied as written in the file
Positions & units	Real positions and dimensions, converted to millimetres whatever the file's unit. Survey coordinates far from the origin keep their precision.
Curves	Round shapes are tessellated at import (32 segments per circle)
⚠ Geometry only	Property sets, materials and relationships (storeys, zones, systems…) are not kept. Re-exporting an imported model gives its geometry, not its BIM data.
Export — Export ▾ › .IFC
Format	IFC4, units in millimetres, with the spatial structure the standard requires (Project › Site › Building › Storey) — files that strict BIM software accepts, not only permissive viewers
Objects	Each object of the scene becomes a building element under its NASSCAD name
Exact geometry	Cube, Cylinder, Tube, Hollow box, Sphere and Cone are written as true parametric shapes (extruded profiles, sphere, cone) — they open as editable solids with their real dimensions, not as triangles. A mirrored or unevenly stretched primitive falls back to triangles rather than being written wrong.
Everything else	Boolean results, generators and imported meshes are written as compact triangulated surfaces
🎨 Colors per face	Kept on export — a multicolour part comes back multicolour when the file is read again
Round trip	Checked by re-reading NASSCAD's own IFC exports with the same engine used at import

⚙ CSG Operations — Union · Subtract · Intersect

⚡ Engine	Booleans run in the NASSCAD Engine (MEDUSA) on your own machine — native Manifold C++, spread over every CPU core. Without MEDUSA, they run in the browser (Manifold WASM, loaded on the first boolean): same results, one core, slower on large models. The engine badge in the CSG panel shows which one is working.
Union	Merges N objects into one solid. Shift+click to select N objects.
Subtract	Subtracts holes from solids. Automatic hole-mode detection.
Intersect	Keeps only the volume common to all selected objects.
Hole Mode	Marks an object as a hole (transparent red). Union with a solid = automatic subtraction.
Progressive CSG	A coarse preview appears immediately, then the full-quality result replaces it silently in the background. The badge ⚡ Refining is shown in between. Sources look hidden during the first pass — that is normal.
Fast path	Objects that do not overlap are merged directly, without the boolean engine. Measured: 200 spheres (19.5 M vertices) in ~3.6 s.
Tree	Displays the CSG construction tree — Union(A, Subtract(B, C))…
Re-run	Non-destructive — rebuilds the sources and replays the operation. Survives Save/Load and Undo/Redo.
Deep Re-run	Replays the whole tree from the leaves in one go. Shown only when the tree is at least 2 levels deep. Change a source, press Deep, everything downstream follows.
CSG⚡ quality	Buttons 32 / 64 / 128 in the menubar — how finely curves are resolved during booleans. Default 128. Does not change the display or the export quality.
Workers	×4 / ×6 / ×8 in the menubar — client-side dispatch thresholds only. The boolean itself is parallelised by the engine across all CPU cores. Applied immediately, no reload.

⌐ Fillet & Chamfer — real CAD edges

Toolbox button Quick Fillet. Rounds or bevels the edges of a solid — the real operation a mechanical CAD package performs, including the blended corners where three edges meet.

◉ Round / ✦ Chamfer	Rounded fillet or straight bevel — switch at any time before applying
Radius R	0.1 – 50 mm, slider or numeric field
Segments	8 / 16 / 32 / 48 / 96 / 192 — smoothness of the rounded surface. 32 is a good default.
⬡ All edges	Fillets every edge of the object in one operation
🖱 Pick edges	Click an edge to select it — hold and drag across several edges to paint-select them. Click again to deselect. Then ⬡ Selected fillets only those; the rest stay sharp.
⬆ Top / ⬇ Bottom	One click adds every edge of the topmost or bottommost flat face — the two most common cases
Edge colors	■ convex · ■ concave · ■ hovered · ■ picked
⚠ If it fails	A radius larger than the local geometry allows will be refused — the operation is rejected rather than producing a broken solid. Reduce R, or pick fewer edges at once.

✏ Sketch.Gen — 2D Sketcher → Extruded Solid

Fullscreen 2D overlay. Draw a closed contour → Extrude → solid in the scene. Double-click a Sketch.Gen object to re-edit it in place.

Drawing tools
⟡ Select (S)	Pick and move entities. Click background to deselect.
╱ Line (L)	Click start, click end. Chain lines to form a polyline.
▭ Rectangle (R)	Click two corners — generates 4 connected segments.
○ Circle (C)	Click center, drag to set radius.
◜ Arc (A)	3-point arc: start → end → through-point.
∿ Bézier (B)	Cubic Bézier curve. Click start, drag controls.
Trim	Click a segment to trim it at its intersections.
Extrusion
H (mm)	Extrusion height — editable numeric field in top bar.
⤴ Extrude → Scene	Closed contour → watertight solid added to the 3D scene. Multi-body supported.
UI & shortcuts
F	Fit view to all entities
G	Toggle grid
T	Toggle light / dark theme inside sketcher
Del	Delete selected entity
Esc / ✕ Close	Exit sketcher and return to 3D view

◠ CircularText.Gen — Curved 3D Text

Shape	∩ arch (top arc) or ∪ smile (bottom arc)
Curve angle	0–340° arc sweep. Negative values = smile. 0 = straight text.
Parameters	Font size, extrusion depth, letter spacing, bevel — 6 fonts
Double-click	Re-opens the dialog pre-filled to edit text or curve live

🔄 Rotation Gizmo

Rotation mode	Double-click an object 3 times (handles → dimensions → rings) — 3 Cura-style rings: ■ Y (blue) · ■ X (green) · ■ Z (red). Drag a ring to rotate. Snap 15°. Double-click again or click on empty space to exit.
Ring size	Constant on screen — the rings keep the same apparent size whatever the zoom, exactly like Cura Slicer.
Angle display	Live angle shown during the drag.

📐 Face Handles — Interactive Resize

Activate	Double-click an object once to show the 6 handles (1st step of the double-click cycle). Drag a handle to resize live. Undo-safe.
4 corner handles	XZ plane resize — change Width and Depth together, keeping the opposite corner anchored.
Top square ■	Y height handle — drag up/down to change object height.
Arrow ↑ (green)	Y lift/lower — moves object vertically. Floor-clamped at Y=0 (no underground).
Drop to ground	Toolbar button — snaps selection bottom face to Y=0. Works on multi-select.
Live dimensions	XYZ labels updated in real time during the drag, rotation-aware.

🧰 Toolbox — Snap · View

Snap	Magnetic grid snap on/off. Each click steps 1 → 0.5 → 0.1 → 0.01 → 0.001 mm → OFF (key S). The five buttons beside it — 1 · .5 · ·1 · ·01 · ·001 — jump straight to a step.
Scale	Magnifier buttons /5 /2 1× ×2 ×5 ×10 — scale the selection uniformly. 1× = back to original size. A multi-selection scales around the group centre.
Zoom speed	Camera buttons /5 /2 1× ×2 ×5 ×10 — how far one notch of the scroll wheel moves the camera. The lit button is the current speed, 1× = normal. Remembered between sessions.
Measure	Shift+click two objects or more: shows the centre-to-centre distance and the real gap between each pair. On/off.
Views	Top · Front · Reset camera · Perspective (keys 1–5).
X-Ray	Every object semi-transparent, all edges visible through the material. On/off.
Feature edges	Draws the sharp (crease) edges of every object. On/off.
⊕CG	Moves the pivot of the selection to its real centre of gravity. The part stays where it is.
Drop to ground	Puts the bottom of the selection exactly on Y=0. Works on multi-selection.
Recenter grid	Brings the grid and all objects back to the centre (after an Alt+right drag).
Pinned reset	Sends every pinned object (📌) back to its pinned position.
Frame	The camera fills the view with the selected object(s).

🎛 Properties Panel

☀ Light	Directional light intensity — 0 (dark) to 2 (very bright). Default 0.7. Global, not per-object.
Color	Click the swatch to open the OS color picker. Also reachable via 🎨 Recolor.
Opacity	0 = transparent, 1 = opaque. Below 1 enables transparent rendering with correct depth sorting.
Solid / Hole	Toggle object mode. Hole = transparent red, auto-subtracted in CSG Union.
Pos / Rot / Dim	Direct numeric input. Pos Y = height of the bottom face above ground. Dim = real dimensions, rotation-aware.
◎ Sphere resolution	Slider 8–256 segs, always visible. Live rebuild. Export at 2× capped 512. The ceiling is set by geometric accuracy (7.5 µm chord error on a 100 mm sphere — finer than any SLA printer), not by the graphics card.
X-Ray mode	Toolbar button — all objects semi-transparent. Reveals hidden or interior geometry. Toggle anytime.
Build volume	Toolbox button — shows your printer's bed and build volume, sitting on the grid. Only the two walls behind the model are drawn, and they switch as you orbit, so nothing ever hides the part. Click to pick the printer among 28 best-selling models (Bambu Lab, Creality from the original Ender-3 to the K2 Plus, Prusa, Elegoo, Anycubic, Voron, Sovol), show the ceiling or hide it. If a part sticks out, the wall on that side turns red and the log says by how many mm.
World grid	A gridded room — floor, walls and ceiling — around your work, so depth and scale read at a glance. It sizes itself to the scene (1 m minimum, then 2 m, 5 m, 10 m…), with a cell of one tenth of the room. While the camera is inside, every face is drawn; zoom out beyond it and only the far walls stay. On/off in the same menu as the build volume.
Hide all	Button right of Build volume — one click hides the build volume and the world grid (the work grid stays). Click again to bring back what was shown.

📐 Alignment

Activate	Shift+click ≥ 2 objects → 📐 Align button or key L — colored 3D handles appear. Click a handle = immediate alignment.
X Axis	Left · Center · Right
Y Axis	Floor · Center · Top
Z Axis	Front · Center · Back
Object snap	Alt+drag on an object — snaps face-to-face to the nearest object. Active when Snap is enabled.

↩ Undo / Redo

Ctrl+Z / Ctrl+Y	200 levels, persisted in the browser — they survive a heavy session without slowing it down.
Scope	Add, delete, move, scale, rotate, CSG, duplicate, import, .gen edit, thread insert. Every change is undoable.
CSG stays coherent	The construction tree is part of each undo step — Re-run still works after Ctrl+Z.
Auto-purge	Oldest steps dropped when the limit is reached. Cleared on new project or file load.

💾 Save and Export

Toolbox button or menubar 📤 Export ▾. At the top of the menu, Include sets what goes into the file: All design, or only the Selected shapes — chosen by default when something is selected. Applies to every format, STEP, IFC, section and JSON project included.

Save	Exports a `.json` project — objects, positions, colors, CSG geometries and construction tree
Load	Reloads a NASSCAD `.json` project — restores the complete scene including generator parameters
Export STL Binary	Native slicer format (Cura, PrusaSlicer, Bambu) — Z-up. 4–5× more compact than ASCII. Quality: 128 / 256 / 512 segs
Export STL ASCII	Human-readable text — legacy tool compatibility
Export OBJ	Wavefront with normals — compatible Blender, FreeCAD
Export 3MF	Native format for Bambu Studio, PrusaSlicer, Cura — per-object colors, Z-up
Export GLB	Binary glTF 2.0 — colors and normals embedded. Draco-compressed variant available (≈ 4–8× smaller)
Export PLY	Stanford polygon format — for scanning or VFX pipelines
Export STEP AP242	B-Rep STEP — opens in Fusion 360, FreeCAD, Autodesk Viewer, Siemens NX
Export IFC4	BIM exchange — exact parametric primitives, per-face colours, millimetre units. See the IFC section.
Export Section SVG/DXF	Horizontal cross-section at Y = N mm → 2D contour as SVG (Inkscape) or DXF (AutoCAD/LibreCAD). Cut height chosen in the dialog.
STL Quality	Buttons 128 / 256 / 512 in the menubar — curve segments at export. 128 is enough for a 0.4 mm FDM nozzle.
📂 IDB Projects	Named projects saved inside the browser — list, save, load, delete. Quota bar displayed.
📁 Folder	Opens the folder containing the NASSCAD file (desktop only)

⚡ NassScript — Integrated JS Console

Access	Menubar button ⚡ Script — opens the script editor
Execution	Runs JavaScript against the scene — create objects, run booleans, batch repetitive work. Supports `await`.
Shortcuts	Ctrl+Enter = Run · Tab = 2 spaces · Ctrl+↑/↓ = history (20 entries)
Example	`addPrimitive('cube'); nasLog('OK','done');`
Documentation	Every function the console can reach, with ready-to-paste recipes: nasscad.com/nasscript_doc.html
⚠ Power tool	Scripts run with full access to the application. Never paste code you have not read.

💾 Memory

NASSCAD reserves its own memory block at startup. Size chosen via 💾 Pool: 512MB / 1GB / 1.5GB / 2GB in the menubar (default 512 MB). Unused geometry is reclaimed automatically.

512 MB (default)	Comfortable for most sessions
1 GB	Recommended for large scenes and big STEP assemblies
2 GB (max)	For the heaviest work — desktop builds make the best use of it
MEM gauge	Bar at bottom right. Hover for detail.
Flush pool	Toolbar button — reclaims memory on demand and reports how much was freed.
Integrity check	Stored geometry is checksummed — silent corruption is detected on load rather than shown as a broken model.

⚠ Performance — measured

Measured on 23/09/2026 with the built-in benchmark script, on an Intel Core i5-9400 (6 cores), 64 GB RAM, NVIDIA RTX 3050 8 GB, Firefox 152, 1920×1080, NASSCAD Engine 3.1. Booleans scale with the number of CPU cores, display with the graphics card. The boolean times below are with MEDUSA; without it, the same operations run in the browser on a single core — same results, slower on large models.

Display — camera orbit, whole scene in view
✅ 60 FPS	Up to 1,000 objects — even at 16.6 M vertices (1,000 spheres at 128 segs)	500 spheres: 0.5 M vertices · 1,000 spheres: 1.1 M / 4.2 M / 16.6 M vertices
⚠ 30 FPS	Around 2,000 objects — whatever their size (2.2 M or 33 M vertices gave the same ~30 FPS)	Still usable; the object count is the limit, not the triangles
🔴 Beyond	More than 2,000 objects or more than ~33 M vertices	Not measured — expect below 30 FPS
Boolean operations — NASSCAD Engine, CSG⚡ 128 unless noted
✅ Instant	Cube − cylinder · two spheres at CSG⚡ 64	0.15 – 0.4 s
✅ Fast	Two spheres at CSG⚡ 128 · a 200 mm plate − 100 holes in one operation	0.4 s · 0.8 s (preview after 0.1 – 0.25 s)
✅ Fast path	Union of 200 spheres that do not touch — 19.5 M vertices, merged without the boolean engine	3.6 s
⚠ Slower	Two spheres at CSG⚡ 256 · CSG⚡ 512 (~1 M triangles in)	1.1 s · 4.0 s (preview after 0.1 s)
🔴 Heavy	Union of 100 overlapping spheres at 128 segs — 3.2 M triangles in, 1.2 M vertices out	12.7 s (preview after 0.5 s)
Memory
Pool AUTO	Sized at startup from the RAM the engine reports as free — 2 GB (the maximum) on a 64 GB machine	Watch the MEM gauge at bottom right
🔴 Saturation	Red MEM gauge — very large CSG history or heavy imports	Save, then ♻ Flush pool or reload the page
Practical tips
· Too many objects? Union parts that do not touch — the fast path merges them into one object in seconds, and the object count is what limits the display · Heavy booleans: work at CSG⚡ 32 or 64, switch to 128 only for the final result — time grows 2 to 4× per step up · Complex CSG: union all the holes first, then subtract once — one operation instead of N · Box-select: drag on an empty zone to select a group — then drag any selected object to move the whole group (snap-aware, single Undo) · Deep Re-run: change the sources, press ↺↺ Deep, the whole tree recomputes on its own · Large booleans: run the NASSCAD Engine (MEDUSA) — the same Manifold, native, on every CPU core instead of one · Big STEP assemblies: run the NASSCAD Engine — it is what gives you per-face colors and files above ~20 MB, not just speed · STL 128 segs: enough for a 0.4 mm FDM nozzle (printer resolution > 0.2 mm)

✅ What NASSCAD Guarantees

Printable geometry	Every primitive and every generator produces a closed, watertight solid — checked, not assumed. What you export slices without repair.
Faithful colors	Imported colors match what the original CAD package shows, per part and per face.
Nothing leaves your machine	No account, no upload, no server. Files are read locally; the optional companion runs on your own computer and listens only to it.
Works offline	A single HTML file plus its companions. No CDN, no network needed once downloaded.
Nothing is destroyed	Boolean operations keep their construction tree — you can always go back, change a source, and replay.

🎬 Authors

NASSCAD V4.7.0 — August 2026
✍ NASSER Architect & Tester	CLIT · Electronics technician · 3D Maker Vision, direction, critical bug identification, quality standards, field testing, technology pivots.
🤖 Claude Developer	Artificial Intelligence · Anthropic Successive Claude models — native CSG engine, watertight primitives, STEP colour decoding verified against the file itself, surgical patches, systematic verification before delivery.
V4.7.0 highlights: native CSG engine (NASSCAD Engine companion, C++/multithreaded) · 18 watertight primitives · Sketch.Gen 2D sketcher · Screw.Gen & Nut.Gen (ISO / ASME) · Gear.Gen · Pipe.Gen · CircularText.Gen · real fillet & chamfer on picked or all edges · STEP AP203/214/242 import with per-part and per-face colours · PMI & GD&T reading · CSG construction tree with non-destructive Re-run · Undo/Redo 200 levels · Box-select · Face handles & rotation gizmo · X-Ray mode · IFC read & write (IFC2X3/IFC4/IFC4X3 in, IFC4 out) · Import STL/OBJ/3MF/GLB/PLY/STEP/IFC · Export STL/OBJ/3MF/GLB/PLY/STEP AP242/IFC4/SVG/DXF · magnetic snap down to 0.001 mm · build volume (28 printers) & world grid · NassScript console

Third-party components — bundled locally, no third-party CDN:
In the browser
· three.js r128 (three.js authors) — MIT — 3D WebGL rendering
· OpenCASCADE Technology 7.4.0 via opencascade.js 1.1.1 (Open Cascade SAS / Sebastian Alff) — LGPL 2.1 with exception — B-Rep CAD kernel: fillet/chamfer, STEP assembly, colour and PMI reading
· occt-import-js (Viktor Kovács) — LGPL 2.1 — STEP import, embeds OpenCASCADE Technology
· web-ifc 0.0.77 (That Open Company) — MPL 2.0 — IFC import (IFC2X3 / IFC4 / IFC4X3)
· Draco 1.5.7 (Google) — Apache 2.0 — mesh compression, glTF/GLB import and export
· helvetiker_regular / bold (MAGENTA Ltd, MgOpen Modata) — MgOpen License
· optimer_regular / bold (MAGENTA Ltd, MgOpen Cosmetica) — MgOpen License
· gentilis_regular / bold (J. Victor Gaultney / SIL International) — SIL OFL 1.1
· nasscad_logs.js (NassLab) — CC BY-NC 4.0 — structured logging module
In the NASSCAD Engine companion (optional, runs on your machine)
· OpenCASCADE Technology 8.0.1 (Open Cascade SAS) — LGPL 2.1 with exception — native STEP reading and tessellation, unmodified DLLs
· Manifold 3.5.3 (Emmett Lalish and contributors) — Apache 2.0 — boolean CSG engine
· oneTBB 2022.2.0 (Intel / UXL Foundation) — Apache 2.0 — multithreading
· Clipper2 1.5.4 (Angus Johnson) — Boost Software License 1.0 — 2D polygon clipping, used by Manifold
· hwloc 2.11.2 (Inria and the Open MPI project) — BSD 3-Clause — CPU topology detection, shipped with oneTBB
Web version only (nasscad.com)
· Google Analytics 4 (Google) — audience measurement, loaded only when NASSCAD is opened from nasscad.com — never when the file is opened locally, from a school portal (ClassLink, Clever, Google Classroom…), with ?edu=1, or when the browser sends Global Privacy Control / Do Not Track — Privacy
Source code of the LGPL / MPL components
· OCCT (tag V8_0_1) · opencascade.js (v1.1.1) · occt-import-js · web-ifc (0.77)
Each component remains under its own license. Full texts: MIT · Apache 2.0 · LGPL 2.1 · OCCT exception · MPL 2.0 · BSL 1.0 · BSD 3-Clause · SIL OFL 1.1

⚖ NASSCAD V4.7.0 License
© 2026 NassLab — Nasser, France
This software is distributed under the Creative Commons BY-NC 4.0 license:
· Personal and non-commercial use — free, redistribution allowed with attribution
· Commercial use — written agreement required from NassLab

This license covers NassLab code only — the third-party components listed above remain under their own licenses.

No implied warranty. The author cannot be held liable for any damage resulting from the use of this software.